I don't think the askari in fez look is quite right for this period, not in the field, anyway (more for formal parade wear, sentry duty at a base or whatever). That chap with the fez in the photo above looks like a guard at some kind of detention camp.
The KAR in the bush in the 50s and 60s tended to dress like this:


When not in the bush an Aussie-style slouch hat with one side turned up seems to have been more common than a fez for headwear. Most pics of troops in fezzes from this era are of colour parties and such at very formal occasions.